Pro-Ject – Phono Box RS2 – First Look
All Images Credit: Pro-Ject
I am always on the prowl looking for new phono amplifiers that are within my budget and provide an array of features and a technical performance that meets my needs. Here is yet another that is on my list.
Pro-Ject has recently introduced what it believes to be one of the most flexible phono stage available. The Phono Box RS2, a fully balanced, fully discrete phono pre-amplifier featuring extensive loading options to accommodate virtually any MM or MC phono cartridge system.
The Austrian audio company claims that this is a “no expense spared” MM and MC phono stage. Besides supporting both RIAA and DECCA equalization curves, the pre-amp uses no operational amplifiers in the L/R signals discreet component signal chains. This they claim leads to a more neutral, natural, dynamic and vivid sound.
The fully balanced circuitry should maintain excellent signal integrity helping to reduce noise. The design providing good signal-to-noise ratios for the following gains:
- 40dB gain – 89dBA re 10mV for MM
- 60dB gain – 79dBA re 1mv for MC
Pro-Ject has provided very good support for matching all styles of cartridge. The RS2 has eight settings for gain, ranging from 40dB to 70dB, eight MM loads from 10pF to 400pF and continually variable MC loading from 10ohms to 1000ohms that allows you to “tune” your MC cartridge.
A unique feature provided by the RS2 is its front panel ability to trim the left/right balance by +-2dB. A front panel switchable subsonic filter is also available that provides a roll-off of 18dB/octave from 20Hz.
The Phono Box RS2 uses split passive equalization for both its RIAA and DECCA curves. This approach is more costly to implement but helps ensure better impedance matching, lower distortion and a more accurate EQ response curve.
For ease of use, all the above adjustments are available on the front panel .
Add all the above to XLR balanced inputs and outputs, plus phono unbalanced inputs and outputs, the inputs of which may be selected from the front panel, and you have yourself a very flexible phono amplifier.
The RS2 comes standard with an external switched mode power supply (not my favourite) that will shortly have the option of being replaced with a high-end linear power supply. This Power Box RS2, is an optional upgrade that is engineered around a purpose designed transformer providing the Phono Box RS2 with a clean and stable 20volt DC supply and a separate 15volt DC output that will drive Pro-Ject turntables. (In my opinion this should be standard for a phono amplifier of this purported caliber).
Technical Specifications:
- Input Impedance – Fixed 47kohms, variable 10 – 1000 ohms
- Loading MM – 50, 100, 150, 200, 250, 300, 350, 400 pF
- Gain MM – RCA: 40, 43, 46, 50 dB (+6dB using XLR)
- Gain MC – RCA: 60, 63, 66, 70 dB (+6dB using XLR)
- Signal To Noise Ratio – MM (40dB): 89dB A-wt (10mV); MC (60dB): 79dB A-wt (1mV)
- THD – < 0,0015% (MM 40dB, 1kHz); < 0,0024% (MC 60dB, 1kHz)
- RIAA accuracy – within 0,4dB/20Hz – 20kHz
- Subsonic filter – at 20Hz with 18dB/octave
- Inputs – RCA & XLR
- Outputs – RCA & XLR
- Power supply – 20V/3A DC; 110 – 240V, 50/60Hz
- Power consumption – 350mA DC < 1 watt standby
Available from January 2021 in either a Black or Silver metal chassis, the Phono Box RS2 has an MSRP of $1,999.00; £1,299.00; €1,499.00
